In a wireless communication system, adjacent base stations, i.e. neighbor base stations, exchange power allocation information using a Relative Narrowband Transmit Power (RNTP) message. A Downlink RNTP (DL RNTP) is a message for interference coordination in the downlink and is transmitted through an X2 interface. In more detail, RNTP informs of whether the transmit power allocated per Resource Block (RB) is greater than a predetermined threshold using 1-bit indicator.
If the maximum transmit power of a RB, which may also be referred to as a Physical RB (PRB) that includes a predetermined number of subcarriers, is not greater than the threshold value, then the indicator is set to 0. This means that the RB is not allocated a power greater than the threshold, and thus, the base station may predict the low interference probability in the PRB.
Otherwise, if the maximum transmit power of the PRB is greater than the threshold, then the indicator is set to 1. In this case, a neighbor base station regards that the transmit power to be allocated to the corresponding PRB is not restricted, and thus, predicts high interference probability in the corresponding RB.
Accordingly, the neighbor base station determines that the RB, for which the indicator is set to 0, is less affected by interference, and thus, allocates the corresponding RB to a cell edge user. In contrast, the neighbor base station determines that the RB, for which the indicator is set to 1, is significantly affected by interference, and thus, allocates the corresponding RB to the cell center user with relatively low transmit power so as to mitigate the interference to neighbor cells. The interference information exchange increases the data transmission/reception overhead as the number of RBs increases due to the increase of the number of neighbor base stations or the increase of the available bandwidth. Also, this related-art method has a drawback in that it is difficult to perform accurate power allocation according to the location of the terminal within the cell. Accordingly, there is a need for an improved interference coordination method and apparatus for use in a mobile communication system.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.